Snail is the invertebrate belong to the phylum Mollusca of kingdom Animalia. Snail is cosmopolitan live in a verity of habitats such is terrestrial, freshwater and marine. Molluscs are the second largest group of organism after insects about 35000 land snails’ species was recognized. They establish their population on moist and shady places. Their diversity and distribution and their effect on other organism are not much explore in tehsil timergara district dir lower. For this purpose, the present study was conducted to explore the diversity and determine the effect on other organism. Snail were collected from the different localities such is the side of river, green grasses,   maize field , tomato field, and from small plant a total 366 specimen were collected and preserved in 80% ethanol in the forensic research lab university of swat. The snails species were identify according the available taxonomic keys. Oxichilus alliarius ,bulimulus guadalapensis, trochulus striolatus and helicellia itala were identified. The highest population of Oxichilus alliarius which is 110 and the lowest population is helicellia itala which is 74. For the presences of helminths parasites both water and alimentary canal were observed under light microscope. The helminths were identified according the available taxonomic keys. Eggs of the helminths parasite encyclostoma duodenals , clonerchis, paragonimus, scihstosoma, toxacara cati, monizia, fasciola hepatica , and larva of helmanths parasite Rhabbditis, skarjabingylus, scihstosoma chitwoodorum, physaloptera maxillaris, microfiliria.  

Key Word: Snail, Diversity, helminths